Taxonomy Tool Roundup

There are quite a few products on the market called taxonomy tools. To choose just a few for a comparative evaluation requires narrowing the field a bit. Since taxonomies are typically used for tagging and searching, a number of taxonomy products integrate taxonomy creation and maintenance features along with capabilities such as auto-categorization, human tagging, or search to provide more complex, full-featured solutions. This article, however, looks at products that facilitate only taxonomy creation and maintenance.

Taxonomy tools are used by individuals who call themselves taxonomists or who otherwise are familiar with best practices for creating taxonomies, including librarians, controlled vocabulary editors, lexicographers, and some information architects. The tools are not difficult to use, but creating a good taxonomy requires specific skills and knowledge of categorization practices. The use of the software alone does not necessarily result in a usable taxonomy, just as a good HTML editing tool does not necessarily result in a good website if the user is not skilled in the techniques of web design.

There are different definitions and types of taxonomies: simple lists of terms with synonyms, hierarchical trees, faceted categories, standard thesauri, and complex ontologies. The products reviewed here serve the creation of all of these types of taxonomies, except for limitations in ontologies. The designation “taxonomy” can refer to all of these or, more specifically, to a hierarchical, tree-type taxonomy. We will refer to taxonomies in the broader sense. An information retrieval thesaurus can be considered a more complex type of taxonomy, which supports not only hierarchical relationships but also associated term relationships, cross-references from nonpreferred (used for) terms. The products evaluated here each support these thesaurus characteristics, so they are marketed as “thesaurus construction tools,” rather than taxonomy tools. Yet thesaurus tools are the best options for creating a simple hierarchical taxonomy as well.

The basic requirement of a taxonomy tool is to maintain terms and their associated relationships and other attributes. The relationships are reciprocal between pairs of terms, so by using a taxonomy tool, the user only needs to create or edit the relationship in one place. If the user decides to rename or delete a term, all its relationships will reflect the change. Support for optional scope notes and user-defined classification categories for each term is also standard in a taxonomy tool.

The products covered in this evaluation all meet the basic requirements and share several additional features. These include designating candidate and approved terms, indicating term creation date and modification date, permitting multiple hierarchies (polyhierarchies), and disallowing illegal term relationships. They all run only on Windows and include online Help. They are available as affordable single-user desktop tools in addition to having multi-user versions and can export taxonomies in platform-neutral formats for use in other systems.

Taxonomy DisplayA thesaurus is typically displayed alphabetically, with relationships and attributes listed at each term, whereas a simple taxonomy, with its emphasis broader-narrower (parent-child) relationships, is typically displayed as a hierarchy. Therefore, a thesaurus and taxonomy tool could present the list of terms more than one way. MultiTes displays the taxonomy in an alphabetical list of all terms. To view a hierarchy of the taxonomy requires selecting the “Hierarchical” or “Top term” options from the Report menu, which generate simple text files to the screen.

Term Display and EditingCreating and editing terms and their relationships is easy and efficient in MultiTes. To view or edit a term’s details involves clicking on the desired term and calling up a new pop-up window. The term window provides the term name, classification, relationships, notes, and other attributes, which are logically grouped. From here the details window of any associated term can also be jumped to, a feature limited in the other tools.

MultiTes has a clean, compact term-editing interface. All types of relationships, categories, and notes can be added by selecting their label code from a single alphabetical drop-down list. The main term-editing drawback is that existing relationships cannot be changed in one step, but rather they have to be deleted and new ones added.

MultiTes allows the creation of relationships to existing terms and the creation of relationships to new terms that the user simultaneously creates. When creating a relationship to a term that does not yet exist in the taxonomy, a pop-up window alerts the user and asks if it should proceed with creating the new term. This is a nice feature, because often it is difficult to remember if the target term of a link already exists.

Taxonomy SearchingTaxonomy navigation is important for the user, who needs to know whether a given term has already been created. In MultiTes, the user simply types the start of the term, with truncation within a word, and hits enter. In addition, an Advanced Search option allows the user to select from terms which start with truncated text, contain text, are flagged, belong to a category, have a status, have a term number, whose date contains text, or whose note contains text. A list of matching terms then appears in the search window. From the list one can jump to an individual record. Another option is copying the list of terms to the clipboard for offline manipulation.

User-Defined Relationships and AttributesThe ability to define relationships, types of notes, and categories of terms is an important set of features for making a taxonomy tool versatile and extensible. More complex, or semantic, types of relationships (such as “produced by,” “owned by,” and “utilized for”) are what can distinguish an ordinary taxonomy from an ontology. MultiTes allows unlimited user definition of relationships, as long as they fall into one of three main categories: hierarchical (broader/ narrower or parent/child), associative (related terms), or equivalent (use/use for). The creation of reciprocal terms is also enforced.

Similarly, MultiTes supports user-defined categories and notes for terms. Categories are often used in taxonomies to classify terms by source, for end use, or for any purpose the taxonomy developer may have. User-defined notes might be desired for different audiences: taxonomists, indexers, and the end users. MultiTes does not support additional user-defined attributes, but there is no reason why the notes field cannot be used for any purpose, such as a physical address for a company name term.

Importing, Exporting, and ReportsMultiTes accepts imported data as a text file, with specifications of one or more relationships or attributes for the terms. The data must follow a specific format but does not use tags. This is the only import format that MultiTes accepts. MultiTes has the advantage over the other tools of accepting imported data not merely as files but also simply as pasted text from a clipboard. This is often a practical way for the user to batch load even just a couple of terms or relationships.

The features of exporting and generating reports are combined in MultiTes, allowing a full range of displays, subsets of terms to include or exclude, and term information to include or exclude. This is in addition to the different output formats. The output formats available are ANSI text, HTML (as a webpage), XML, and CSV delimited, or an output directly to the printer. There is a full range of display formats and choices for inclusion/exclusion.